Some refrigeration cycle apparatuses are configured to switch between cooling and heating by switching a flow of refrigerant discharged from a compressor to any of first and second heat exchangers. In such a refrigeration cycle apparatus, in general, a volume of a refrigerant flow path is greater in the first heat exchanger (an outdoor heat exchanger) than in the second heat exchanger (an indoor heat exchanger). In this case, since an optimal amount of refrigerant at which a coefficient of performance (COP) is maximized is greater in cooling than in heating, an amount of refrigerant is greater in cooling than in heating. Therefore, since an amount of refrigerant in cooling is excessive in heating, a refrigerant tank circuit which collects refrigerant excessive in heating to the refrigerant tank has been proposed. For example, Japanese Patent Laying-Open No. 2014-119153 (PTD 1) discloses such a refrigerant tank circuit. In an air conditioner described in this document, refrigerant excessive in heating is stored in a refrigerant tank (receiver) in the refrigerant tank circuit.